This paper presents a case study of the application of an engineering technique for a typical distributed parameter system, namely, the modelling, optimal state estimation and control of an ingot handling process. The...
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ISBN:
(纸本)0080316700
This paper presents a case study of the application of an engineering technique for a typical distributed parameter system, namely, the modelling, optimal state estimation and control of an ingot handling process. The major procedure used for model development is to transform a partial differential equation and its corresponding boundary conditions, as derived from the first principle laws of the process, into a single discrete state space model describing the thermal state of the ingot during the various operational phases by carrying out the discretization in both time and space simultaneously. The results of a comparison the experimental data gathered from an instrumented production soaking pit and the model's output show excellent agreement between the model and real process.
By making use of a modified two-step algorithm for integrated system optimisation and parameter estimation and modelling sub-processes as shift models, a procedure is developed for the optimising control of large-scal...
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ISBN:
(纸本)0080316697
By making use of a modified two-step algorithm for integrated system optimisation and parameter estimation and modelling sub-processes as shift models, a procedure is developed for the optimising control of large-scale processes. The shift models, which contain parameters that are estimated on the same time scale as the optimisation problems, enable a decentralised structure to be obtained. Sub-process interconnections are accounted for in the model parameters and coordination between sub-problems is achieved through a modifier vector. The technique is applicable to the steady-state optimisation of systems which have no subsystem interconnection inputs in the local performance objectives or have them present in additive terms.
作者：
March, A.R.CEGB
Regional Engineering Dep Bristol Engl CEGB Regional Engineering Dep Bristol Engl
control system development for nuclear power plants can lead to increased electrical output, and hence lower overall costs. This paper describes a system which has been developed and installed at Oldbury-upon-Severn P...
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ISBN:
(纸本)0080316670
control system development for nuclear power plants can lead to increased electrical output, and hence lower overall costs. This paper describes a system which has been developed and installed at Oldbury-upon-Severn Power Station, to provide control of the boiler steam temperature. The plant has several features which precluded the use of simple three term controllers, and modelling and predictive control techniques were used. These are discussed in some detail.
Existing adaptive autopilots do not usually have an energy saving capability. In addition the control performance in rough seas often deteriorates so significantly that the autopilot is switched to a conventional PID ...
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ISBN:
(纸本)0080325424
Existing adaptive autopilots do not usually have an energy saving capability. In addition the control performance in rough seas often deteriorates so significantly that the autopilot is switched to a conventional PID controller. The first problem often arises from inaccurate approximations in the formulation of the energy cost criterion and the second from poor modelling of the sea wave disturbances. These problems are tackled here by formulating a new dynamic cost function, system description and modelling approach. The LQG control strategy is then used to design an optimal controller to perform the course keeping and course changing autopilot tasks. An explicit self-tuning scheme is employed to provide adaptation in varying weather conditions. Simulation results are presented to demonstrate the performance of the proposed autopilot.
Model identification and parameter estimation have an impeccable pedigree in the controlsystems area;yet the problem contexts in which the resulting models are employed are seldom as thoroughly researched. The issue ...
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ISBN:
(纸本)0080325424
Model identification and parameter estimation have an impeccable pedigree in the controlsystems area;yet the problem contexts in which the resulting models are employed are seldom as thoroughly researched. The issue of problem identification must be a first step in any practical project, often determining irreversibly the direction of its later thrust. While a broad systems stance is necessary, it is not in itself sufficient. There is a strong current in contemporary operational research which addresses this subject of problem structuring. This paper reviews these approaches with the aim of illustrating how they can help us avoid producing the right answer to the wrong problem.
The need to make more efficient use of energy resources by improved methods of control, the deferrment of expensive pipework reinforcement or replacement and the requirement to accommodate different loading patterns o...
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ISBN:
(纸本)0080325424
The need to make more efficient use of energy resources by improved methods of control, the deferrment of expensive pipework reinforcement or replacement and the requirement to accommodate different loading patterns on sections of the gas network have made the requirement for effective feedback control essential. Gas distribution systems are large and complex and a major problem in applying conventional feedback techniques is the cost and reliability of transmitting the data necessary for automatic control. In order to overcome these difficulties, state estimation techniques have been investigated as a means of providing information about a distribution system from a minimum number of measurement points. The theoretical background to the study is reviewed including the modelling technique and the results of experimental work which has been performed on a distribution network in order to verify the techniques developed are presented. The results show that state estimation techniques have considerable potential for this type of application.
A method for combining and communicating a priori qualitative and quantitative process knowledge is presented. Upon this basis discrete time models may be structured both for lumped and distributed capacities with a m...
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ISBN:
(纸本)0080325424
A method for combining and communicating a priori qualitative and quantitative process knowledge is presented. Upon this basis discrete time models may be structured both for lumped and distributed capacities with a modest effort. The resulting sparse model structures are robust against varying operating conditions and thus well suited for multivariable adaptive control. Application of the model structuring method is demonstrated both in an identification example on a two stage evaporator simulation and in an experimental control example on a chemical fixed bed reactor. The method is demonstrated to give good performance.
作者：
Hess, R.A.Univ of California
Davis Dep of Mechanical Engineering Davis CA USA Univ of California Davis Dep of Mechanical Engineering Davis CA USA
A simple structural model of the human operator has been discussed. The model is descriptive rather than predictive in nature and has its basis in an hypothesized feedback structure involving the human neuromuscular s...
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ISBN:
(纸本)0080316719
A simple structural model of the human operator has been discussed. The model is descriptive rather than predictive in nature and has its basis in an hypothesized feedback structure involving the human neuromuscular system. The model appears capable of unifying much of the data base for single axis tracking and to modify the way in which manual control engineers view the human's fundamental capabilities and limitations. Work is currently underway in extending the handling qualities assessment technique to multiloop and multi-axis tasks.
Granger's concept of causality is used in this paper to study the interrelationship between money, income and prices in India. Four alternative methods - the Sims' method, the cross-correlations method, the tr...
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ISBN:
(纸本)0080325424
Granger's concept of causality is used in this paper to study the interrelationship between money, income and prices in India. Four alternative methods - the Sims' method, the cross-correlations method, the transfer function approach and the autoregressive modelling approach - are used for the analysis. The methods yield substantial concensus on the directions of causality among the variables of interest. Money supply, in both its narrow and broad senses, emerges as an important causal variable so far as nominal national income and general price level are concerned. There is no reverse feedback, except from nominal income to the broad concept of money supply. The tenets of monetarism thus derive some support from the empirical exercise.
On the basis of previous works of the authors, concerning modelling of international economic cooperation, a model is presented of cooperation of three blocks of countries with different politico-economic goals. The m...
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ISBN:
(纸本)0080316727
On the basis of previous works of the authors, concerning modelling of international economic cooperation, a model is presented of cooperation of three blocks of countries with different politico-economic goals. The multiperson cooperative game theory is applied in this model. The characteristic function of the game is constructed with due account of the politico-economic specifics of such an international cooperation, in which there participate countries having differing, sometimes even conflicting, politico-economic objectives, as well as neutral countries. For particular block the so called 'levels of economic preparedness' are determined, defining at the same time the 'depth' of specialization.
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